1. Field of the Invention
The present invention relates to an extrusion molding adapted to an opening trim, or the like, of a car provided with a hard insert in which reinforcement portions and space portions. are formed alternately longitudinally, and relates to a method of producing such an extrusion molding.
The present application is based on Japanese Patent Application No. Hei. 11-187363, which is incorporated herein by reference.
2. Description of the Related Art
As shown in FIG. 5, an opening trim of a car is constituted by an elongated base 100 approximately U-shaped in section, and any insert 1 buried in the base 100. The base 100 is made of a soft resin such as soft polyvinyl chloride (PVC), thermoplastic olefin (TPO), or the like. The base 100 includes a pair of lip portions 101 which are formed opposite to each other so as to be protruded from opposite inner surfaces, respectively, of the base 100. On the other hand, as shown in FIG. 2, the insert 1 includes a plurality of U-shaped reinforcement portions 10, and bridge portions 11 connecting the plurality of reinforcement portions 10 to one another successively at intervals of a predetermined distance, by which gap portions 12 are formed between respective adjacent ones of the reinforcement portions 10. Further, the U-shape of the base 100 is held by the reinforcement portions 10 and the base 100 is made deformable in bending by the presence of the bridge portions 11 and the gap portions 12.
Accordingly, the opening trim thus formed is incorporated into a vehicle so that an attachment portion of the vehicle is sandwiched between the pair of lip portions 101. As a result, the attachment portion is clamped by the pair of lip portions 101, so that the securing strength is secured in a region of the presence of each reinforcement portion 10. On the other hand, the opening trim can be deformed in bending along the shape of the attachment portion in a region of the presence of each gap portion 12 so that the opening trim is assembled into the vehicle securely.
The opening trim is produced by an extrusion molding method in which the insert 1 and a molten resin for forming the base 100 are extruded simultaneously while supplying the insert and supplying the molten resin to the circumference of the insert.
In the background-art opening trim, however, there was a disadvantage that a surface of the base 100 was uneven between the region where the reinforcement portions 10 were present and the region where the gap portions 12 were present, so that the background-art opening trim looked unattractive and felt unpleasant to the touch.
The present invention has been attained upon such circumstances and an object thereof is to smooth a surface shape of an extrusion molding which is reinforced with a hard insert having reinforcement portions and gap portions, thereby improving quality in external appearance of the extrusion molding.
In order to solve the above problem, according to an aspect of the present invention, there is provided an insert-containing extrusion molding comprising: a hard insert disposed so as to have a gap portion in at least a portion and so as to be deformable in bending in the gap portion; a foam layer in which the insert is buried and with which the gap portion is filled; and a skin layer with which a surface of the foam layer is coated; wherein the foam layer has an expansion ratio in a portion where the foam layer abuts on a surface of the insert is smaller than an expansion ratio in a portion where the gap portion is filled with the foam layer.
According to another aspect of the present invention, there is provided a method of producing an insert-containing extrusion molding by extruding a hard insert so as to have a gap portion in at least a portion, a foamable resin and a skin resin at once to thereby produce an extrusion molding having the insert, a foam layer in which the insert is buried, and a skin layer with which a surface of the foam layer is coated, wherein a surface of the skin layer is smoothed by performing extrusion molding while controlling the extrusion molding from the the skin layer side so that the foam volume in a portion opposite to a surface of the insert is smaller than the foam volume in a portion where the gap portion is filled when the foamable resin is foamed.